RESUMO
Oral bacteria are implicated not only in oral diseases but also in gut dysbiosis and inflammatory conditions throughout the body. The periodontal pathogen Aggregatibacter actinomycetemcomitans (Aa) often occurs in complex oral biofilms with Streptococcus gordonii (Sg), and this interaction might influence the pathogenic potential of this pathogen. This study aims to assess the impact of oral inoculation with Aa, Sg, and their association (Aa+Sg) on alveolar bone loss, oral microbiome, and their potential effects on intestinal health in a murine model. Sg and/or Aa were orally administered to C57Bl/6 mice, three times per week, for 4 weeks. Aa was also injected into the gingiva three times during the initial experimental week. After 30 days, alveolar bone loss, expression of genes related to inflammation and mucosal permeability in the intestine, serum LPS levels, and the composition of oral and intestinal microbiomes were determined. Alveolar bone resorption was detected in Aa, Sg, and Aa+Sg groups, although Aa bone levels did not differ from that of the SHAM-inoculated group. Il-1ß expression was upregulated in the Aa group relative to the other infected groups, while Il-6 expression was downregulated in infected groups. Aa or Sg downregulated the expression of tight junction genes Cldn 1, Cldn 2, Ocdn, and Zo-1 whereas infection with Aa+Sg led to their upregulation, except for Cldn 1. Aa was detected in the oral biofilm of the Aa+Sg group but not in the gut. Infections altered oral and gut microbiomes. The oral biofilm of the Aa group showed increased abundance of Gammaproteobacteria, Enterobacterales, and Alloprevotella, while Sg administration enhanced the abundance of Alloprevotella and Rothia. The gut microbiome of infected groups showed reduced abundance of Erysipelotrichaceae. Infection with Aa or Sg disrupts both oral and gut microbiomes, impacting oral and gut homeostasis. While the combination of Aa with Sg promotes Aa survival in the oral cavity, it mitigates the adverse effects of Aa in the gut, suggesting a beneficial role of Sg associations in gut health.
Assuntos
Aggregatibacter actinomycetemcomitans , Perda do Osso Alveolar , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Streptococcus gordonii , Animais , Perda do Osso Alveolar/microbiologia , Perda do Osso Alveolar/etiologia , Perda do Osso Alveolar/patologia , Perda do Osso Alveolar/metabolismo , Camundongos , Biofilmes/crescimento & desenvolvimento , Boca/microbiologia , Modelos Animais de Doenças , Masculino , Gengiva/microbiologia , Gengiva/metabolismoRESUMO
PURPOSE: To compare the effect of thermal cycling and erosive challenge on color change, surface roughness, surface loss and biofilm deposition of three resin-based composites. METHODS: Three resin-based composites that reproduce the color of gingival tissues [two nanohybrid composites (A and B) and a giomer (C) ] were tested before and after distinct challenges [ thermal cycling (TC) and erosive challenge (EC) ] in regard to its color stability, surface roughness, surface loss and biofilm deposition. Surface roughness and surface loss specimens (n=10) were measured with an optical profilometer and, color stability (n=10) was measured with a spectrophotometer. Biofilm deposition (n=5) was measured after 3 and 24 hours by safranin staining. RESULTS: Two-way ANOVA test was performed to analyze color change, roughness and surface loss. A significant color change was detected for resin-based composites (P< 0.05) and its interaction with tested challenges (P< 0.05). The highest color variation was observed on the giomer after erosive challenge. Surface loss was not different between tested groups (P= 0.708). The roughness was significantly higher in specimens submitted to thermal cycling (P> 0.05). For biofilm quantification, after 3 and 24 hours, ANOVA (3-way) detected significance for the interaction of challenges and resin-based composites (P< 0.05 and P< 0.05, respectively). All resin-based composites presented color changes after challenges; higher roughness was observed after thermal cycling for all resin-based composites tested, without significant surface loss; and higher biofilm deposition was observed on the giomer samples when submitted to erosive challenge after 3 and 24 hours. CLINICAL SIGNIFICANCE: Pink esthetic is as important as dental esthetics and some restorative materials can mimic gingival tissue. However, the tested giomer must be indicated with caution, since it presented significant changes after thermal and acid challenges.
Assuntos
Resinas Compostas , Materiais Dentários , Cor , Estética Dentária , Teste de Materiais , Propriedades de SuperfícieRESUMO
This study was designed to investigate whether there is a correlation between the findings of optical coherence tomography (OCT) and polarized light microscopy (PLM) when these techniques are used to evaluate standard enamel white-spot lesions developed by distinct cariogenic challenges. Bovine enamel fragments (N = 168) were randomly allocated into 6 experimental groups according to the microbiologic model (Streptococcus mutans UA159, Streptococcus sobrinus ATCC 33478, or mixed S mutans and S sobrinus) and carbohydrate sources (1% sucrose or combined 1% sucrose and 1% starch). Specimens were examined by OCT and PLM every day within a period of 7 days. Five measurements of demineralization depth were recorded for each specimen, and means were calculated. Data were analyzed with analysis of variance and Tukey tests (α = 0.05), and a correlation test was performed. All cariogenic challenges created sub-superficial lesions. In both the OCT and PLM analyses, the demineralization depth reached its peak between days 6 and 7 of the cariogenic challenge, except for the group challenged with S sobrinus supplemented with combined sucrose and starch; for that group, demineralization peaked on day 5 in the OCT analysis. There was a significant correlation between OCT and PLM (P = 0.00; r = 0.842). This preliminary study suggests that OCT is a reliable, nondestructive method to measure the demineralization depth of enamel white-spot lesions, which can be useful for the laboratory and has potential for clinical studies. Using the 1% sucrose and S mutans model for 6 days is a simple and effective method to induce enamel caries-like lesions without compromising the depth and morphologic features of the obtained lesions.
Assuntos
Cárie Dentária , Microscopia de Polarização/métodos , Tomografia de Coerência Óptica/métodos , Desmineralização do Dente , Animais , Bovinos , Cárie Dentária/diagnóstico , Esmalte Dentário , HumanosRESUMO
PURPOSE: To assess the effects of three different dental adhesive systems on the formation of secondary root caries, in vitro, with a standardized interfacial gap in a filled cavity model. METHODS: 40 sound human molars were selected and randomly assigned to four experimental groups: Clearfil SE Bond (CSEB), Xeno III (X-III), Scotchbond Multi-Purpose Plus (SBMP) and negative control (NC) without an adhesive system. After the standardized Class V cavity preparations on the buccal and lingual surfaces, restorations were placed with resin composite (Filtek Z250) using a standardized interfacial gap, using a 3 x 2 mm piece of 50 microm metal matrix. The teeth were sterilized with gamma irradiation and exposed to a cariogenic challenge using a bacterial system with Streptococcus mutans. Depth and extension of wall lesions formed and the depth of outer lesions were measured by software coupled with light microscopy. RESULTS: For wall lesion extension the ANOVA test showed differences between groups except between X-III and SBMP (P=0.294). The Tukey's test of confidence intervals indicated smaller values for the CSEB group than for the others. For wall lesion depth the CSEB group also presented the smallest mean values of wall lesion depth when compared to the others (P<0.0001) for all comparisons using Tukey's test. Regarding outer lesion depth, all adhesives showed statistically similar behavior. SEM evaluation of the morphologic appearance of caries lesions confirmed the statistical results showing small caries lesion development for cavities restored with CSEB adhesive system, which may suggest that this adhesive system interdiffusion zone promoted a good interaction with subjacent dentin protecting the dental tissues from recurrent caries.
Assuntos
Resinas Compostas , Restauração Dentária Permanente/métodos , Cimentos de Resina , Cárie Radicular/prevenção & controle , Análise de Variância , Adesivos Dentinários , Humanos , Dente Serotino , Cárie Radicular/microbiologia , Estatísticas não Paramétricas , Streptococcus mutansRESUMO
PURPOSE: To assess the total viable bacteria in infected dentin after sealing with glass-ionomer cement containing 1% metronidazole, 1% ciprofloxacin and 1% cefaclor. METHODS: 40 children were selected, with ages ranging from 4-10 years, with primary teeth with active carious lesions without any pulpal involvement. The patients were divided randomly into two groups in accordance to the glass-ionomer cement used to seal the carious lesions: Group 1 (control, n=20), sealing with conventional glass-ionomer cement; and Group 2 (test, n=20) sealing with glassionomer cement including antibiotics. The infected dentin was collected both before and 24 hours after the sealing of the cavities and, after inoculation in blood agar, all the plates were incubated in containers kept at 37 degrees C for 5 days in an atmosphere of 85% N2, 10% CO2 and 5% H2, for subsequent counting of total viable bacteria. RESULTS: The results were analyzed using the Wilcoxon and Mann-Whitney tests. The glass-ionomer cement with 1% of metronidazole, 1% of ciprofloxacin and 1% of cefaclor showed a significantly greater reduction in microbiota in the infected dentin in comparison to the reduction with the conventional ionomer cement (P< 0.01), with a mean reduction of 98.65% of all viable bacteria. The infected dentin after sealing with glass-ionomer cement with antibiotics showed, using scanning electron microscopy, the presence of bacterial aggregates, intertubular dentin with exposure of collagen fibers, and dentin tubules.
Assuntos
Antibacterianos/administração & dosagem , Cárie Dentária/tratamento farmacológico , Cárie Dentária/microbiologia , Dentina/microbiologia , Cimentos de Ionômeros de Vidro/uso terapêutico , Bactérias/efeitos dos fármacos , Cefaclor/administração & dosagem , Criança , Pré-Escolar , Ciprofloxacina/administração & dosagem , Contagem de Colônia Microbiana , Restauração Dentária Permanente/métodos , Dentina/ultraestrutura , Cimentos de Ionômeros de Vidro/química , Humanos , Metronidazol/uso terapêutico , Microscopia Eletrônica de Varredura , Estatísticas não ParamétricasRESUMO
It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P. intermedia, among others, to persist and establish chronic infections in the host.
Assuntos
Biofilmes/crescimento & desenvolvimento , Porphyromonas gingivalis/fisiologia , Prevotella intermedia/fisiologia , Aderência Bacteriana , Biomassa , Disbiose/microbiologia , Humanos , Periodontite/microbiologia , Porphyromonas gingivalis/classificação , Prevotella intermedia/classificação , Prevotella intermedia/genéticaRESUMO
BACKGROUND: Antibacterial photodynamic therapy (aPDT) is a promising adjunctive therapy to the treatment of caries lesions, mainly in the minimally invasive approach to preserve dental tissue and favor its repair. Here we analyzed both the efficacy of aPDT in reducing the bacterial load in cariogenic biofilms and the indirect effect of noxious components produced by aPDT on the viability of dental pulp cells. METHODS: The aPDT protocol was established using 0.025g/mL methylene blue (MB) and 5min pre-irradiation time. A continuous-wave diode laser (660nm, 0.04cm(2) spot size, 40mW, 60s, 60J/cm(2) and 2.4J) was used in punctual and distance modes to excite the MB. The protocol was first tested against Streptococcus mutans (U159) biofilms produced in 96-well microplates, and then evaluated on caries-like affected human dentin discs of three thicknesses. The number of colony forming units (CFU) was compared between groups. Discs were then assembled in metallic inserts to produce an artificial pulp chamber and allow investigation of the indirect effects of aPDT on dental pulp cells by the 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay. Data were analyzed using Student's t test or one-way analysis of variance (ANOVA) followed by the Tukey's test at a significance level of 5%. RESULTS: Bacterial load reduction was observed in biofilms produced both in the microplates (p<0.05) and on the caries-like affected dentin discs (81.01% or mean reduction of log21.010±0.1548; p=0.0029). The cell viability of aPDT and control group was similar (p>0.05). CONCLUSIONS: aPDT may be considered a promise adjunctive therapy for deep carious lesions.
Assuntos
Biofilmes/efeitos dos fármacos , Cárie Dentária/tratamento farmacológico , Azul de Metileno/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Streptococcus mutans/efeitos dos fármacos , Carga Bacteriana/efeitos dos fármacos , Sobrevivência Celular , Cavidade Pulpar/efeitos dos fármacos , HumanosRESUMO
Sports dentistry has been considered a prominent area of dentistry because dental health can limit the abilities of athletes, both professional and nonprofessional, in their training and competition. Dental decay is associated with the frequent use of carbohydrates, recommended as an energy source for exercise. Strong indications exist regarding the possibility to use saliva as a performance determinant and for evaluation and prescription of physical activity. This study evaluated the salivary profiles (pH, flow rate, mutans streptococci and Lactobacillus counts) and decayed, missing, and filled teeth of 18 female soccer players (13 to 19 years old) of the Olympic Training and Research Center of São Paulo, before and after a training session. The salivary flow rate presented a significant reduction after training; however, there was no significant alteration in pH. Fifty percent of the players presented 10(5) to 10(6) mutans streptococci, and 66% presented 10(3) Lactobacillus. Several salivary components protect against microorganisms that cause superior respiratory tract infections (common in athletes), as well as participating in the remineralization mechanism during cariogenic challenges. Thus, due to the salivary flow rate reduction in this population with a high number of cariogenic microorganisms, noncariogenic drink ingestion at regular intervals and maintenance of hydration levels during training, are suggested.
Assuntos
Saliva/metabolismo , Saliva/microbiologia , Futebol/fisiologia , Adolescente , Adulto , Índice CPO , Carboidratos da Dieta/uso terapêutico , Ingestão de Líquidos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus/isolamento & purificação , Esforço Físico/fisiologia , Saliva/química , Taxa Secretória , Streptococcus mutans/isolamento & purificaçãoRESUMO
This study was conducted to examine the oral condition and the salivary and microbiological parameters associated with dental caries in 62 children with cerebral palsy, who came from households of low socioeconomic status (Study Group). This group had mixed (6 to 11 years old) and permanent (11 to 16 years old) dentition. Dental examinations were performed to measure dental caries, plaque index, salivary levels of mutans streptococci and lactobacilli, salivary flow rate, pH of stimulated saliva, and buffer capacity of saliva. A group of 67 non-handicapped children from similar socioeconomic backgrounds also were examined using these parameters (Control Group). Data were analyzed statistically by non-parametric tests and by correlation. The results showed that children with cerebral palsy who had permanent dentitions had a higher mean decayed, missing and filled surfaces index, as well as a higher plaque index for both sexes. Microbiological examination revealed higher levels of mutans streptococci among Study Group subjects with mixed dentition than in the Control Group. Also, lactobacillus counts were higher in the Study Group, regardless of sex or dentition. With respect to salivary flow rate, pH and buffering capacity, lower mean values were obtained for the Study Group.
Assuntos
Paralisia Cerebral/complicações , Cárie Dentária/etiologia , Adolescente , Soluções Tampão , Criança , Contagem de Colônia Microbiana , Índice CPO , Índice de Placa Dentária , Dentição Mista , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus/crescimento & desenvolvimento , Masculino , Medição de Risco , Fatores de Risco , Saliva/metabolismo , Saliva/microbiologia , Saliva/fisiologia , Taxa Secretória/fisiologia , Classe Social , Estatísticas não Paramétricas , Streptococcus mutans/crescimento & desenvolvimentoRESUMO
PURPOSE: Cerebral palsy (CP) is a major severe childhood disability and its prevalence is increasing, particularly among premature low-weight newborns. The oral conditions observed demonstrate the need for home and professional care for these individuals. This study aimed to investigate dental caries, plaque index, time of eruption, malocclusion, bruxism and motor oral skills in a group of 62 CP children (study group). METHODS: The results were compared to those obtained for a control group with 67 normal children. Nonparametric statistical tests including the Mann-Whitney test, Fisher's Exact test (P), Chi-square test (chi2), and Cochran's Q test were used according to the nature of the variables studied, with the level of significance set at P<.05. RESULTS: The results showed a significantly higher DMFS index for CP children with permanent dentition of both sexes when compared to normal children. A significantly higher plaque index was also observed in the study group. A high tendency to delayed eruption of permanent molars and significantly higher percentages of malocclusion and bruxism were observed in the study group with permanent dentition. Residual food and mouth breathing have been frequently found in CP children. CONCLUSIONS: Earlier preventive measures for CP patients are required because they are a high-risk group for dental caries.
Assuntos
Paralisia Cerebral/complicações , Doenças Dentárias/complicações , Adolescente , Fatores Etários , Bruxismo/complicações , Estudos de Casos e Controles , Paralisia Cerebral/fisiopatologia , Distribuição de Qui-Quadrado , Criança , Índice CPO , Deglutição/fisiologia , Cárie Dentária/complicações , Índice de Placa Dentária , Feminino , Humanos , Masculino , Má Oclusão/complicações , Mastigação/fisiologia , Respiração Bucal/complicações , Fatores Sexuais , Estatísticas não Paramétricas , Erupção DentáriaRESUMO
BACKGROUND: Aggregatibacter actinomycetemcomitans serotypes are clearly associated with periodontitis or health, which suggests distinct strategies for survival within the host. OBJECTIVE: We investigated the transcription profile of virulence-associated genes in A. actinomycetemcomitans serotype b (JP2 and SUNY 465) strains associated with disease and serotype a (ATCC 29523) strain associated with health. DESIGN: Bacteria were co-cultured with immortalized gingival epithelial cells (OBA-9). The adhesion efficiency after 2 hours and the relative transcription of 13 genes were evaluated after 2 and 24 hours of interaction. RESULTS: All strains were able to adhere to OBA-9, and this contact induced transcription of pgA for polysaccharide biosynthesis in all tested strains. Genes encoding virulence factors as Omp29, Omp100, leukotoxin, and CagE (apoptotic protein) were more transcribed by serotype b strains than by serotype a. ltxA and omp29, encoding the leukotoxin and the highly antigenic Omp29, were induced in serotype b by interaction with epithelial cells. Factors related to colonization (aae, flp, apaH, and pgA) and cdtB were upregulated in serotype a strain after prolonged interaction with OBA-9. CONCLUSION: Genes relevant for surface colonization and interaction with the immune system are regulated differently among the strains, which may help explaining their differences in association with disease.
RESUMO
The purpose of this study was to evaluate the degree of demineralization of artificially induced caries-affected human dentin by an in vitro microbiological method. The occlusal surfaces of 6 human molar teeth were abraded until a flat surface was obtained, and the enamel was removed to expose the occlusal dentin surface. These teeth were sectioned in 12 halves in the vestibular-lingual direction and divided into 3 groups according to the period length of the microbiological essay (n = 4): G1, 7 days; G2, 14 days; and G3, 21 days. The surfaces of all specimens were protected by an acid-resistant nail varnish, except for a window where the caries lesion was induced by a Streptoccocus mutans biofilm in a batch-culture model supplemented with 5% sucrose. The specimens were then analyzed by optical coherence tomography (OCT) with a super-luminescent light diode (Λ = 930 nm) with 6.0-µm lateral and longitudinal resolution (in the air). Qualitative and quantitative results (images and average dentin demineralization, respectively) were obtained. The mean demineralization depths were (µm) 235 ± 31.4, 279 ± 14, and 271 ± 8.3 in groups 1, 2, and 3, respectively. In addition, no significant change was observed in the lesion mean depth from 7 days of cariogenic challenge on. In conclusion, OCT was shown to be an efficient and non-invasive method to detect the depths of lesions caused by demineralization. Further, a seven-day demineralization time was considered sufficient for caries-affected dentin to be obtained.
Assuntos
Testes de Atividade de Cárie Dentária/métodos , Cárie Dentária/diagnóstico , Dentina/ultraestrutura , Tomografia de Coerência Óptica/métodos , Biofilmes , Dentina/química , Humanos , Técnicas In Vitro , Propriedades de Superfície , Fatores de TempoRESUMO
OBJECTIVE: The objective of this study was to evaluate the disinfection degree of dentine caused by the use of diode laser after biomechanical procedures. STUDY DESIGN: Thirty teeth were sectioned and roots were autoclaved and incubated for 4 weeks with a suspension of Enterococcus faecalis. The specimens were randomly divided into 3 groups (n = 10): G1, instrumented with rotary files, irrigated with 0.5% sodium hypochlorite and 17% EDTA-T, and then irradiated by 830-nm diode laser at 3 W; G2, the same procedures as G1 but without laser irradiation; and G3, irrigation with saline solution (control). Dentin samples of each third were collected with carbide burs and aliquots were sowed to count viable cells. RESULTS: The disinfection degree achieved was 100% in G1 and 98.39% in G2, when compared to the control group (G3). CONCLUSION: Diode laser irradiation provided increased disinfection of the deep radicular dentin in the parameters and samples tested.
Assuntos
Dentina/microbiologia , Desinfecção/métodos , Enterococcus faecalis/efeitos da radiação , Lasers Semicondutores/uso terapêutico , Preparo de Canal Radicular/métodos , Contagem de Colônia Microbiana , Desinfecção/instrumentação , Ácido Edético , Humanos , Irrigantes do Canal Radicular , Hipoclorito de SódioRESUMO
The purpose of this study was to evaluate the degree of demineralization of artificially induced caries-affected human dentin by an in vitro microbiological method. The occlusal surfaces of 6 human molar teeth were abraded until a flat surface was obtained, and the enamel was removed to expose the occlusal dentin surface. These teeth were sectioned in 12 halves in the vestibular-lingual direction and divided into 3 groups according to the period length of the microbiological essay (n = 4): G1, 7 days; G2, 14 days; and G3, 21 days. The surfaces of all specimens were protected by an acid-resistant nail varnish, except for a window where the caries lesion was induced by a Streptoccocus mutans biofilm in a batch-culture model supplemented with 5 percent sucrose. The specimens were then analyzed by optical coherence tomography (OCT) with a super-luminescent light diode (Λ = 930 nm) with 6.0-µm lateral and longitudinal resolution (in the air). Qualitative and quantitative results (images and average dentin demineralization, respectively) were obtained. The mean demineralization depths were (µm) 235 ± 31.4, 279 ± 14, and 271 ± 8.3 in groups 1, 2, and 3, respectively. In addition, no significant change was observed in the lesion mean depth from 7 days of cariogenic challenge on. In conclusion, OCT was shown to be an efficient and non-invasive method to detect the depths of lesions caused by demineralization. Further, a seven-day demineralization time was considered sufficient for caries-affected dentin to be obtained.
Assuntos
Humanos , Testes de Atividade de Cárie Dentária/métodos , Cárie Dentária/diagnóstico , Dentina/ultraestrutura , Técnicas In Vitro , Tomografia de Coerência Óptica/métodos , Biofilmes , Dentina/química , Propriedades de Superfície , Fatores de TempoRESUMO
OBJETIVO: avaliar a atividade antimicrobiana da associação de um adesivo ortodôntico com um verniz de clorexidina e timol. MÉTODOS: foram utilizados 32 pré-molares humanos divididos em 4 grupos. O grupo 1 consistiu do grupo controle, no qual o adesivo utilizado para a colagem do braquete não estava associado a nenhum agente antimicrobiano. Os grupos 2, 3 e 4 foram colados com um sistema adesivo associado a um verniz de clorexidina e timol. Os grupos 3 e 4 foram armazenados em água por 7 dias e 30 dias, respectivamente, enquanto os corpos de prova do grupo 2 foram, logo depois da colagem, colocados em ágar semeado com Streptococcus mutans por 48h a 37ºC. RESULTADOS: os grupos experimentais, com exceção do grupo controle, apresentaram atividade antimicrobiana com tendência de redução do seu potencial de ação com maior tempo de imersão em água. CONCLUSÃO: a associação do verniz de clorexidina a um sistema adesivo utilizado em Ortodontia apresenta-se vantajosa pela sua atividade antimicrobiana.
OBJECTIVE: To assess the antimicrobial activity resulting from the association of an orthodontic adhesive with chlorhexidine-thymol varnish. METHODS: Thirty-two extracted human premolars were used, divided into four groups. In Group 1, the control group, the adhesive used to bond the bracket was not associated with any antimicrobial agent. Groups 2, 3 and 4 were bonded with an adhesive system associated with chlorhexidine-thymol varnish. Groups 3 and 4 were stored in water for 7 days and 30 days, respectively, while the specimens from group 2 were, soon after bonding, placed on agar seeded with Streptococcus mutans for 48 hours, at 37º C. RESULTS: The experimental groups, with the exception of the control group, showed antimicrobial activity whose action tended to decline commensurately with the amount of time that they remained immersed in water. CONCLUSIONS: The association of chlorhexidine-thymol varnish with an adhesive system used in orthodontics proved to be advantageous due to its antimicrobial activity.
Assuntos
Humanos , Antibacterianos , Clorexidina/administração & dosagem , Clorexidina/uso terapêutico , Adesivos Dentinários , Dente Pré-Molar , Crescimento Bacteriano/prevenção & controle , Higiene BucalRESUMO
Actinobacillus actinomycetemcomitans está implicado como o agente etiológico da periodontite juvenil localizada. Este organismo possui inúmeros fatores de virulência que podem interferir no reparo tissular. 50 isolados de A. actinomycetemcomitans de pacientes com periodontite foram examinados para avaliar outros possíveis fatores de virulência. Neste estudo, foi avaliada a produçäo de cápsula, DNase, coagulase, fibrinolisina, atividade proteolítica, hemolisina e bacteriocina, assim como hemaglutinaçäo, sensibilidade ao soro, aderência às células epiteliais, hidrofobicidade e virulência de A. actinomycetemcomitans. Todos os isolados foram resistentes para todos os tipos de soro utilizados. 70 por cento a 94 por cento dos isolados foram alfa-hemolíticos e aglutinaram todos os tipos sanguíneos. A maioria dos isolados produziu substâncias antagonistas e apresentaram baixa hidrofobicidade. Nenhum dos isolados foi patogênico para camundongos. Pouco se sabe, sobre a açäo e como esses fatores podem agir no desenvolvimento da doença periodontal, sendo necessários estudos adicionais para uma aplicaçäo em termos de sistemática e de patogênese
Assuntos
Aggregatibacter actinomycetemcomitans , Periodontite Agressiva/etiologia , VirulênciaRESUMO
Dentre os microorganismo isolados nos casos de insucesso, o Enterococcus faecalis é comumente encontrado. A irradiação laser apresenta características antimicrobianas que podem auxiliar no tratamento endodôntico. Este estudo tem por objetivo avaliar o grau de descontaminação provocado pelo uso do laser de diodo de alta potência na dentina radicular em profundidade, após preparo químico-cirúrugico in vitro. Utilizaram-se 30 raízes de dentes unirradiculares esterelizadas em autoclave, as quais foram inoculadas por E. faecalis durante 4 semanas e divididas em 3 grupos. Grupo 1: instrumentação rotatória com hipoclorito de sódio 0,5% e creme Endo PTC, irrigação com EDTA-T 17% e posterior irradiação com laser de diodo de alta potência por 5 segundos com 4 repetições, na potência de 3W; Grupo 2: instrumentação com Grupo 1, sem irradiação; e Grupo 3: apenas irrigação com 20 mL de solução fisiológica estéril. Os espécimes tiveram suas paredes dentinárias desgastadas e as raspas, bem como o cilindro externo restante de dentina, foram imersoso em 1 mL de água peptonada. Assim, alíquotas foram semeadas em meio mEnterococcus. Os resultados foram tratados estatisticamente pelo teste Kruskal-Wallis com método de comparação Dunn e apresenta diferenças significantes entre os grupos (p<0,05). Em porcentagens, a redução da contaminação provocada pelo Grupo 1 foi de 100% e pelo Grupo 2, de 98,39%, ambas em relação ao Grupo 3 (controle). A irradiação do laser de diodo nos parâmetros e amostras testadas foi eficaz na redução da contaminação em profundidade da dentina radicular frente ao Enterococccus faecalis.
Assuntos
Desinfecção , Enterococcus faecalis , Lasers Semicondutores , Descontaminação , Dentina , Endodontia , Hipoclorito de SódioRESUMO
Resumo: Apesar do grande número de estudos, permanecem, ainda, contradiçöes a respeito de aspectos fisiológicos, sorológicos e genéticos de S.sanguis e S.mitis, que refletem em sua classificaçäo.Assim, foram verificadas 72 características fisiológicas de cepas de S.mitis e de S.sanguis biotipos I e II isolados de placa dental.Os resultados, além de revelarem a caracterizaçäo fisiológica das cepas, demonstraram a importância das provas de produçäo de ácidos a partir de arbutina, celobiose e salicina, hidrólise de arginina e tolerância a 40 por cento de bile para a sua diferenciaçäo.Dessa forma, foi sugerida a inclusäo destes testes nos esquemas de identificaçäo dessas espécies, em adiçäo aos comumente utilizados.Além disso, as cepas padräo utilizadas demonstraram, em algumas provas, comportamento oposto às de idêntico biotipo isoladas de placa dental, sendo preconizado, entäo, que os estudos taxonômicos näo devam se basear unicamente no comportamento das cepas padräo.
Assuntos
Arbutina , Streptococcus sanguis , Celobiose , Fenômenos Fisiológicos Bacterianos , Técnicas In VitroRESUMO
The purpose of this study was to evaluate the effect of acid conditioning and occlusal sealant on microbial colonization of pit and fissures submitted to ameloplasty or left intact. Human enamel blocks containing fissures prepared from the occlusal surfaces of unerupted third molars were implanted in occlusal surfaces of unerupted third molars were implanted in occlusal fillings in molars of 12 patients for seven, 30, 60, and 120 days. After seven days of exposure to the oral environment, the pit and fissure blocks were removed and found to be colonized, mainly with gram-positive coccal flora. The acid-etching procedure itself reduced the number of cultivable microorganisms by about 95//. Subsequent application of occlusal sealant caused a gradual decrease of the remaining viable microorganism throughout the experiment. Despite the decrease of 100//after acid etching in most of the fissures submitted to ameloplasty, the occlusal sealant did not lead to a subsequent significant reduction